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HKS Style Dump Pipe Install

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Hi people, i decided to give something back to the ns.com community caus i have asked alot of questions and why not do something for everyone else! Not sure how useful this will be for people, just a guide i made to help the less confident person to do something themselves! Hope you enjoy!

Before we get started on the actual install, ill just run through the parts etc to get you started!!! The dump pipe in question is a HKS Style split dump pipe with a 2.5 inch outlet. (I put it onto my 3 inch front pipe, so it does fit).

Dump Pipe



Firstly, tools, you will need the basic tool set to complete the change. Including defiantly:

- 13 mm spanner/socket to remove the nuts/bolts from the turbo to stock dump pipe.

- 15 mm spanner to remove the front pipe from the cat.

- Jack to ......jack up the car! :)

- Stands so you dont get squashed!!!!!! Very important!


What you get with the pack:

- dump pipe

- 2 gaskets


And the extra parts which you will need:

- 3 studs/nuts to replace the ones that are in the stock dump/front pipe.

- 1 extra stud/nut to be placed at the bottom right of the turbo(looking from front of car) as I will explain later

- 2 bolts/nuts to replace the older underside bolts for the turbo/dump.

- 1 larger diameter o2 sensor, can use 300zx o2 sensor (or adaptor)

- Optional – gasket for front pipe to cat depending on how careful you are.



Step 1.

Have the car on a flat surface, find a suitable jacking point at the front of the car, and jack it up so you have reasonable distance to work under the car and have some movement. Place the stands at the jacking points just before the front wheels.


Step 2.

Using your 13mm spanner remove the 2 bolts from the top of the turbo/dump connection.

Top Bolts



Then get under the car, and remove the nuts/bolt from the underside 3 positions.

Underside Bolts



Remember these will all be very firmly attached so maybe use some wd-40 before you do it to loosen it up a bit and make it bit easier. You will need some muscle to get them off!!

My brother already had his EGR disconnected with the addition of his manifold, so if you still have that, you will need to disconnect it before going any further. I didn’t actually disconnect it myself, so I have no instructions for it, but basically you just unscrew all the bolts holding it onto the body, and remove. You will need to block up the pipe that comes from your pod/airbox into the EGR which can be done by purchasing a cap to tighten over the top.

Removed EGR Pipe




Step 3.

Now that the dump is disconnected from the turbo. We can remove the front pipe from the cat, just to make it easier to assemble. I was originally going to remove the dump from the front pipe, but after seeing that it was quite difficult to do so! And when reassembling putting the gasket on etc would make things a lot harder.

My front pipe was connected to my cat by 15mm bolts. So once you have undone this, you can proceed to carefully pull the dump/front pipe from under the car.



Step 4.




When you have the stock dump out, comparing the two you can defiantly see the restriction. This dump pipe only has a 2.5 outlet, but I think it should flow a lot better being of the split design…..that and its shiny!!!

You will now need to remove the stock dump, from your front pipe. Myn was connected with I believe 14mm bolts/nuts. Once these are unbolted, separate the two and are ready to put the new dump onto the front pipe.

At this point, you will need to put the new studs you purchased into the new dump pipe so you can connect it onto the front pipe. The old studs are connected to the old dump, and I dont think its worthwhile trying to get them out as they are probably fused onto the turbo pretty well! Tighten these up so there is no chance of them coming off and then you can proceed.

You are provided in the kit, a gasket for the dump to front and also for the dump to turbo. You will need some kind of gasket adhesive to join the semi-metal gasket they supply. Once you have applied the adhesive to front pipe flange and also the dump pipe, put the gasket over the top, put the dump onto the front and bolt up. Apparently one hour semi-dries the gasket adhesive, but I would leave it 24 hours before starting the car just to be safe!!!


Front View of Dump



Step 4.

Before you go to put the dump on the turbo. As I mentioned earlier, you will need one extra stud which will fit into the turbo on the bottom right.


Pesky Extra Bottom Stud



This is defiantly needed for this particular dump pipe, as there is physically not enough room to slide a bolt in. Make sure you put this in before attempting to refit the dump or you will have to remove!!

If you choose to replace the gasket from turbo->dump you are supplied one, and basically do the same as before, with applying the gasket adhesive to both flanges and then placing the gasket on. I chose to reuse the metal gasket I had on myn as it had been replaced not that long ago.

Although it is possible to refit by yourself, it is very useful to have some help to steady things so its easier to affix the dump back onto the turbo without cross threading or any nasty occurrences which can defiantly happen J. Once you have put the dump on in place, tighten all the nuts/bolts.

You will also have to apply gasket adhesive to the front pipe/cat section before you tighten it! Once you have applied the adhesive there, tighten the bolts on that, making sure you hook it up properly to the bracket. Once you have tightened it there, make sure all the nuts/bolts on the turbo/dump side are firm, and also make sure the dump/front pipe nuts are tight as well to avoid any leaks.


Step 5.

You should have already purchased the necessary item for your o2 sensor. This particular dump has a bigger thread than the older threads, so you will need to purchase a o2 sensor with a bigger thread. I went to a wreckers yard and purchased a z32(300zx) item, which screws in perfectly! They are around $35 depending on where you purchase from.


o2 Sensor Comparison



Screw this into the hole at the top of the dump pipe, connect to the plug your old o2 sensor came from, and you are basically done!


Final View




You are now done! BUT too bad you are not really supposed to start the car for a while(~24 hours) to allow the gasket adhesive to dry! I am not sure if it really matters or not, but was told to leave it, so I did.

The next day after fitting, my first drive of it seemed like an improvement in lower down torque but I would have to get it on dyno to see results, I would think a max of 10rwkw, but could be wishful thinking! Who knows! But for around $200 it removes the stock dump restriction and gives me something shiny in my engine bay!

Hope I was able to help someone who wants to install the same dump, if I missed anything please tell me and I can edit the post and get some help if u arent sure!


Thanks to Shao for supplying the dumps, jbonevia for advice on the o2 sensor, and chef_32 for helping me install the dump on my car. And also my brother(silvia), the other half of SpankyS13 who i did the first of our two installs on, and i kinda stuffed it up :unsure: and a bolt got cross threaded and caused some headaches!!! But yes, enjoy the read!!

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Note: Instead of purchasing a new O2 sensor, you can simply head to your local auto shop and get a Thread minimiser. It's basically a small washer/screw looking thing that has a thread on the outside ( to fit the dump pipe ) and a small thread on the inside ( to screw the O2 sensor in to ). These are about $5.


Very comprehensive article, Spanky. Well done. These dump pipes also SOUND awesome!



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